fix(un-default-parameter): handle parameters with gap (#124)

pionxzh · Mar 26, 2024 · 1458630 · 1458630
1 parent 95d3d00
commit 1458630
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Showing 5 changed files with 54 additions and 3 deletions.
diff --git a/packages/ast-utils/src/identifier.ts b/packages/ast-utils/src/identifier.ts
@@ -42,7 +42,6 @@ export function isValidIdentifier(
 export function generateName(input: string, scope: Scope | null = null, existedNames: string[] = []): string {
     const cleanName = input
         .replace(/^@/, '')
-        .replace(/^_+/, '')
         .replace(/_+$/, '')
         .replace(/_+/, '_')
         .replace(/^\.+/g, '')

diff --git a/packages/unminify/src/transformations/__tests__/un-default-parameter.spec.ts b/packages/unminify/src/transformations/__tests__/un-default-parameter.spec.ts
@@ -25,6 +25,24 @@ function test(x = 1, y = 2, b, z = "hello", e = world(), f = true) {
 `,
 )
 
+inlineTest('default parameters - With gap',
+  `
+function test(a) {
+  var b = arguments.length > 1 ? arguments[1] : undefined;
+  var e = arguments.length > 4 && undefined !== arguments[4]
+    ? arguments[4]
+    : world();
+  var z = arguments.length > 6 && arguments[6] !== undefined ? arguments[6] : "hello";
+  var _param_3 = 1;
+}
+`,
+  `
+function test(a, b, _param_2, _param_3_1, e = world(), _param_5, z = "hello") {
+  var _param_3 = 1;
+}
+`,
+)
+
 inlineTest('default parameters - ArrowFunctionExpression',
   `
 const test = (a, b) => {

diff --git a/packages/unminify/src/transformations/runtime-helpers/babel/createForOfIteratorHelper.ts b/packages/unminify/src/transformations/runtime-helpers/babel/createForOfIteratorHelper.ts
@@ -90,7 +90,7 @@ export const transformAST: ASTTransformation = (context, params) => {
                     left = j.variableDeclaration('var', [j.variableDeclarator(_result)])
                 }
                 else {
-                    const tempVariableName = generateName('_value', scope)
+                    const tempVariableName = generateName('value', scope)
                     left = j.identifier(tempVariableName)
                     const assignment = j.assignmentExpression('=', left, _result)
                     body.unshift(j.expressionStatement(assignment))

diff --git a/packages/unminify/src/transformations/smart-rename.ts b/packages/unminify/src/transformations/smart-rename.ts
@@ -125,9 +125,12 @@ function handlePropertyRename(j: JSCodeshift, objectPattern: ObjectPattern, scop
         let newName = key.name
 
         // if the newName is not a valid identifier, _{newName} is used instead
-        if (!isValidIdentifier(newName) || isDeclared(scope, newName)) {
+        if (!isValidIdentifier(newName)) {
             newName = generateName(`_${newName}`, scope)
         }
+        else if (isDeclared(scope, newName)) {
+            newName = generateName(newName, scope)
+        }
 
         renameIdentifier(j, scope, value.name, newName)
         property.shorthand = newName === value.name

diff --git a/packages/unminify/src/transformations/un-default-parameter.ts b/packages/unminify/src/transformations/un-default-parameter.ts
@@ -1,3 +1,5 @@
+import { assertScopeExists } from '@wakaru/ast-utils/assert'
+import { generateName } from '@wakaru/ast-utils/identifier'
 import { isLogicalNot, isUndefined } from '@wakaru/ast-utils/matchers'
 import { isVariableIdentifier } from '@wakaru/ast-utils/reference'
 import { createJSCodeshiftTransformationRule } from '@wakaru/shared/rule'
@@ -93,6 +95,9 @@ function handleBody(j: JSCodeshift, path: ASTPath<FunctionDeclaration | Function
     const body = (path.node.body as BlockStatement).body
     if (body.length === 0) return
 
+    const scope = path.scope
+    assertScopeExists(scope)
+
     const params = path.node.params
 
     const bodyInThreshold = body.slice(0, BODY_LENGTH_THRESHOLD)
@@ -206,6 +211,19 @@ function handleBody(j: JSCodeshift, path: ASTPath<FunctionDeclaration | Function
                     return false
                 }
 
+                // insert placeholder parameter when there is a gap
+                if (normalMatch.index >= params.length) {
+                    for (let i = params.length; i < normalMatch.index; i++) {
+                        if (params[i]) continue
+
+                        const scope = path.get('body', 'body', index).scope
+                        assertScopeExists(scope)
+
+                        const parameterName = generateName(`_param_${i}`, scope)
+                        params.push(j.identifier(parameterName))
+                    }
+                }
+
                 params.splice(normalMatch.index, 0, identifier)
                 return false
             }
@@ -220,6 +238,19 @@ function handleBody(j: JSCodeshift, path: ASTPath<FunctionDeclaration | Function
                     return false
                 }
 
+                // insert placeholder parameter when there is a gap
+                if (defaultMatch.index >= params.length) {
+                    for (let i = params.length; i < defaultMatch.index; i++) {
+                        if (params[i]) continue
+
+                        const scope = path.get('body', 'body', index).scope
+                        assertScopeExists(scope)
+
+                        const parameterName = generateName(`_param_${i}`, scope)
+                        params.push(j.identifier(parameterName))
+                    }
+                }
+
                 params.splice(defaultMatch.index, 0, j.assignmentPattern(identifier, defaultParam))
                 return false
             }